DE 2 026 509 A discloses a cutting head for a hair and/or beard cutting appliance, the cutting head comprising a stationary comb shaped as a basically tubular laterally extending body, the tubular body comprising two laterally extending bent protruding sections facing away from each other, wherein each bent section comprises a first wall portion and a second wall portion that extend into a common tip portion, the first wall portion and the second wall portion surrounding a guide area for a movable blade, wherein the bent sections comprises a plurality of slots in which to-be-cut hairs can be trapped and guided towards the movable blade during a cutting operation. The movable blade comprises a basically U-shaped profile that cooperates with the first and the second bent section, wherein each leg of the U-shaped profile comprises an outwardly bent edge portion extending into the guide area defined by the respective first and second wall portion, the edge portion further comprising a toothed cutting edge for cutting trapped hair in a relative motion between the toothed cutting edge of the movable blade and a toothed edge of the stationary comb defined by the plurality of slots in the first and the second bent section.
U.S. Pat. No. 2,102,529 A discloses a hair clipping apparatus comprising a stationary shear blade and a movable shear blade, wherein the movable shear blade comprises lateral bevelled margins that are provided with serrations that define teeth of respective outer shear edges. The fixed shear blade of the hair clipping apparatus may be arranged as a sheet of resilient steel material, wherein the movable shear blade is arranged in a slot defined by the stationary shear blade for relative reciprocating motion with respect to the stationary shear blade. The stationary shear blade may be arranged as a folded shear blade, thereby providing a first wall portion and a second wall portion, wherein the movable shear blade is arranged between the first wall portion and the second wall portion of the stationary shear blade.
For the purpose of cutting body hair, there exist basically two customarily distinguished types of electrically powered appliances: the razor, and the hair trimmer or clipper. Generally, the razor is used for shaving, i.e. slicing body hairs at the level of the skin so as to obtain a smooth skin without stubbles. The hair trimmer is typically used to sever the hairs at a chosen distance from the skin, i.e. for cutting the hairs to a desired length. The difference in application is reflected in the different structure and architectures of the cutting blade arrangement implemented on either appliance.
An electric razor typically includes a foil, i.e. an ultra thin perforated screen, and a cutter blade that is movable along the inside of and with respect to the foil. During use, the outside of the foil is placed and pushed against the skin, such that any hairs that penetrate the foil are cut off by the cutter blade that moves with respect to the inside thereof, and fall into hollow hair collection portions inside the razor.
An electric hair trimmer, on the other hand, typically includes generally two cutter blades having a toothed edge, one placed on top of the other such that the respective toothed edges overlap. In operation, the cutter blades reciprocate relative to each other, cutting off any hairs that are trapped between their teeth in a scissor action. The precise level above the skin at which the hairs are cut off is normally determined by means of an additional attachable part, called a (spacer) guard or comb.
Furthermore, combined devices are known that are basically adapted to both, shaving and trimming purposes. However, these devices merely include two separate and distinct cutting sections, namely a shaving section comprising a setup that matches the concept of powered razors as set out above, and a trimming section comprising a setup that, on the other hand, matches the concept of hair trimmers.